Re: [PATCH] trace-cmd: add a kernel memory leak detector

[Steven Rostedt <rostedt@goodmis.org>]

On Tue, 23 Jun 2015 16:06:39 -0700
Josef Bacik <jbacik@fb.com> wrote:

> I needed to track down a very slow memory leak so I adapted the same approach
> trace-cmd profile uses to track kernel memory allocations.  You run this with
> 
> trace-cmd kmemleak

Note, I'm still playing with this.

> 
> and then you can kill -SIGUSR2 <trace-cmd pid> to get current status updates, or
> just stop the process when you are ready.  It will tell you how much was lost
> and the size of the objects that were allocated, along with the tracebacks and
> the counts of the allocators.  Thanks,
> 
> Signed-off-by: Josef Bacik <jbacik@fb.com>


> diff --git a/trace-kmemleak.c b/trace-kmemleak.c
> new file mode 100644
> index 0000000..2e288fe
> --- /dev/null
> +++ b/trace-kmemleak.c

Please add a copyright notice here. You can add your name as author but
more importantly, please state what license this is under. See
trace-record.c for details.

> @@ -0,0 +1,552 @@
> +#define _LARGEFILE64_SOURCE
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <stdio.h>
> +#include <getopt.h>
> +#include <signal.h>
> +
> +#include "trace-local.h"
> +#include "trace-hash.h"
> +#include "list.h"
> +
> +#define memory_from_item(item)	container_of(item, struct memory, hash)
> +#define memory_from_phash(item)	container_of(item, struct memory, phash)
> +#define leak_from_item(item)	container_of(item, struct memory_leak, hash)
> +#define edata_from_item(item)	container_of(item, struct event_data, hash)
> +#define stack_from_item(item)	container_of(item, struct stack_trace, hash)
> +



> --- a/trace-record.c
> +++ b/trace-record.c

> @@ -3703,6 +3721,7 @@ static void add_hook(struct buffer_instance *instance, const char *arg)
>  }
>  
>  enum {
> +	OPT_kmemleak	= 249,
>  	OPT_bycomm	= 250,

Ug, I realized I never applied your bycomm patch.

I'll need to look at that now too. Egad, I've been putting off
trace-cmd for to long. I need to start getting back to it!

-- Steve

>  	OPT_stderr	= 251,
>  	OPT_profile	= 252,
> @@ -3738,7 +3757,7 @@ void trace_record (int argc, char **argv)